My note on this: network people are used to do this interactively, this is possibly reason guys from GoBGP are doing it the same way (only from CLI/API). Netflow rules are not very persistent in nature, much less than usual routes. r.
That is true, currently you can just define it in static protocol and receive or announce it by BGP.
I think that we should expand static protocol to allow adding or deleting routes interactively. There are some problematic behavioral details in it; e.g., how we should handle interactive removal of a route from configuration. Should we have two independent sets of routes, one added/removed by reconfiguration, one interactively? Or should we allow to remove interactively one from configuration? If so, should it respawn during reconfiguration?